Hot-air heating apparatus.



6. ST. JOHN.

HOT AIR HEATING APPARATUS.

APPLICATION FILED JULY 31, 1908.

970,117. Patented Sept. 13,1910.

2 SHEETS-SHEET 1.

0. ST. JOHN.

HOT AIR' HEATING APPARATUS.

APPLIOATION FILED JULY a1, 1908.

Patented Sept. 13, 1910.

2 SHEETS-SHEET 2.

Invenibr UNITED STATES PfgENT OFFICE.

CARLISLE ST. JOHN, OF DES MOINES, IOWA.

HOT-AIR HEATING APPARATUS.

To all whom it may concern:

Be it known that I, CARLIsLE ST. JOHN, a citizen of the United States,residing at Des Moines, in the county of Polk and State of Iowa, haveinvented a certain new and useful Hot-Air Heating Apparatus, of whichthe following is a specification.

The objects of my invention are to provide a hot air furnace of simpleand durable construction, so arranged that a maximum amount of the heatgenerated by the fire will be utilized in heating air, to thereby effectan economy in fuel; to provide a furnace of this kind in which the draftpassageways are readily accessible, so that they may be quickly andeasily cleaned out; to provide a furnace of this kind in which the sidewalls of the furnace, or portions thereof, may be quickly and easilyI'QIIIOVBd for the purpose of providing access to the interior of thefurnace, at any point, in making repairs or replacing parts; to providea fun nace of this kind in which the joints are ar ranged so as to bepacked with a suitable packing, thus allowing for the expansion andcontraction of the metal parts; also to provide a furnace of this kindarranged with sheet metal parts for retaining the packing at the joints,and preventing any leakage of gases at said joints.

My invention consists in the construction, arrangement and combinationof the various parts of the device, whereby the objects contemplated areattained, as hereinafter more fully set forth, pointed out in my claims,and illustrated in the accompanying drawings, in which Figure 1 shows ahorizontal, sectional view through the central portion of a furnaceembodying my invention, part of said view being taken on a line abovethe upper hot air drum, and part of the view being taken on a line belowthe upper hot air drum. Fig. 2 shows a side elevation of a furnaceembodying my invention with the outer casing on one side cut away andportions of both heating drums being broken away to show the interiorconstruction, the flanges on both of the clean-out door openings in theheating drums being in section and the cover of the radiating device ontop of the combustion chamber also being shown in section. Fig. 3 showsan enlarged. detail sectional view through a portion of the lowerradiating drum and the pipe that connects it with the flue and also thehot air Specification of Letters Patent.

Application filed July 31, 1908.

Patented Sept. 13, 1910.

Serial No. 446,286.

pipe which leads upwardly through the pipe that connects the lowerradiator with the flue.

Referring to the accompanying drawings, I have used the referencenumeral 10 to indicate the combustion chamber of the furnace. At thefurnace front is a door 11, leading to the combustion chamber above thegrate, a door 12 leading to the ash pit below the grate, and a draftdoor 13 above the door 11. This portion of the device is of the ordinaryconstruction and is designed to be operated in the ordinary manner.

The furnace base comprises an annular rim 19 having on its upper surfacea series of flanges. Each flange comprises an upright central portion 20and two upright inwardly inclined end portions 21. These flanges arespaced apart and between each pair of flanges is a stationary lug 22adjacent to the outer edge of the base 19. At certain intervalsthroughout the base 19, the lugs are omitted. This is done for thefollowing reason: The furnace wall is made of sheet metal in segmentalsections, each of which sections extend from the base to the top of thefurnace. Each section is so shaped that its lower edge will rest on topof the base 19, the parts thereof that are adjacent to the flanges 20and 21 being designed to stand on the outer sides of said flanges, andthe parts adjacent to the lugs 22 being designed to stand on the innersides of said lugs, as shown in Fig. 1.

The sheet metal walls are indicated by the numeral 23, and the sideedges thereof are provided with outwardly projecting flanges 24. Inorder to connect the adjacent flanges of two sections, I provide a sheetmetal con necting piece 25, substantially U-shaped in cross section,designed to overlap the edge portions 24 of two adjacent furnace wallsections.

The furnace front is made of a cast metal portion 26 having its sideedges formed with two flanges 27 and 28, spaced apart and designed toreceive between them, the adjacent edges of the furnace wall and also toreceive a packing material to thereby provide for contraction andexpansion in the furnace wall and at the same time maintain air tightjoints.

The dome or top of the furnace casing is indicated by the referencenumeral 29 and fixed thereto and projecting downwardly therefrom is aflange 30 having its lower edge extended downwardly at 31. The flange 30rests upon a cast metal flange 32. This flange is provided with adownwardly and outwardly projecting portion 33 upon which the flange 30of the dome rests. It is obvious that by this means, the upper end ofthe furnace wall may be quickly, easily andconveniently attached to thefurnace top and that it may also be readily removed when desired.

The fire box 10 is arranged eccentrically relative to the furnace wallas shown in Fig. 1 of the drawings. In such an arrangement there is aconsiderable space between the fire box and the interior of the furnacewall and this space is utilized for the purpose of containing theradiating drums. There are two upper radiating drums exactly alike, butentirely independent of each other, and a lower radiating drum. Both theupper drums and the lower drum comprise a hollow body portion 36 and 39,as shown in Fig. 1 of the drawings, so formed that the inner edgesconform with the fire box, and the outer edges conform with the furnacewall. The products of combustion from the fire box pass through thepipes 37 into the rear of the radiating drums 36 down through the pipes38 at the forward ends of said drums into the forward ends of the lowerradiating drum 39, back to the rear of said drum 39, and out through theupright, and horizontal flue pipes 40 and 41. On the interior of theflue 40 is a hot air pipe 43, as clearly shown in Fig. 3, open at bothends and intended only for the purpose of providing additional radiatingsurface, so that the products of combustion in passing through the flue,will come in contact with the outer surface of the pipe 43 and warm it.In both of the radiator drums, 36 and 39, I provide a number of uprighthot air pipes 44, open at both ends for the purpose of conducting airthrough said drums to be heated by the products of combustion passingaround them.

In order to provide for cleaning out the hot air drums, I form anopening at the for ward end of each drum, surrounded by a flange 45, andsaid flanges are covered by the hinged doors 46. At the back of thelower drum 39 is a pipe 47 extended through the furnace wall, said wallbeing provided with a door 48, the construction being similar to theparts 45 and 46, as shown in Fig. 1, whereby the outer end of the pipemay be closed. In this way, the operator may have access to the interiorof the lower drum at the rear for the purpose of cleaning out the same.On the outer face of each of the radiating drums is a series of ribs 49for the purpose of increasing the radiation from the drum.

The means for connecting the lower radiating drum with the flue pipe 40is clearly shown in Fig. 3. In said view, the reference numeral. 50indicates the bottom of the radiating drum and 51 the top thereof. Theouter side of the drum is not shown in said figure. At the bottom of theflue pipe 40 is an annular flange 52, I-shaped in cross section, havingits upright port-ion adjacent to the inner surface of the flue pipe 40and its horizontal portion under the part 51 of the radiating drum. Atthe bottom of the flue pipe 40 is a flange 53 resting on top of the part51, and said parts, 51, 52, and 53, are connected by the bolts 54, andin order to form an air tight joint between the top of the flue pipe 40and the outer surface of the air pipe 43, I provide a cast metal head 55designed to fit around the pipe 43 and having a downwardly projectingflange 56 adj acent to the pipe and so arranged that packing materialmay be inserted between the flange 56 and the pipe 43. At the outerportion of the head 55 are two downwardly projecting flanges 57 and 58designed to receive the top of the pipe 40 between them and alsoprovided with a space to receive packing material. In order to hold thepacking material in position, I provide a sheet metal veneering 59designed to cover the space between the flange 56 and the pipe 43, andalso to extend under the space between the flange 58 and the pipe 40, asshown in Fig. 3. Thus said packing material is firmly held in positionand an air tight oint provided. Another one of the very importantfunctions of the sheet metal veneering 59 is to provide for thedurability of the furnace. It is well known that cast metal, whensubjected to great variation of temperatures, is liable to crack, andsmoke and gases may leak through the cracks thus formed. Sheet metal ofitself is not sufficient to form certain parts of the furnace whichrequire great strength. By combining the sheet metal veneering 59 withthe rigid and strong cast metal member to which it is attached, Iprovide means whereby, in the event that the cast metal should crack,the sheet metal veneering would then cover the crack sufliciently toprevent the leakage of gas or smoke, and at the same time the sheetmetal veneering does not need to be heavy or strong as required towithstand strain, and the cast metal will protect the sheet metalveneering from the action of the fire even if small cracks are developedin the cast metal. The lower end of the air pipe 43 is connected withthe bottom of the lower radiating drum in the same way as the pipe 40 isconnected with the top of the lower radiating drum, as shown in Fig. 3.In practical use with this portion of the apparatus, it is obvious thatall of the products of combustion arising from the furnace will passfirst through the upper radiating drums, and then downwardly through thelower ones, and then out through the flue. The heat arising from the topof the combustion chamber will be materially increased by the radiatingdevice set forth and the products of combustion throughout their entirecourse will surround the air pipes in the drum and in the pipe 40, sothat a maximum amount of the heat arising from the furnace will beutilized in heating the air within the furnace walls.

I claim as my invention:

1. In a device of the class described, the combination of a combustionchamber, a furnace wall surrounding the combustion chamber and arrangedconcentrically relative thereto, the front of the furnace wall beingcloser to the combustion chamber than the other parts, two radiatingdrums at the upper portion of the space between the combustion chamberand the furnace wall, each of said upper radiating drums having its rearend spaced apart from a rear central line, and being extended to a pointspaced apart from the front central line, and also being tapered from amaximum width at its rear end to a minimum at its front end, means forproviding communication direct from the upper portion of the combustionchamber to the rear end of each radiating drum, a radiating drum belowthe upper drums extended from points spaced apart from a front centralline all around the space between the combustion chamber and the furnacewall, pipes connnunicating between the front ends of the upper drums andthe front ends of the lower drum to convey the products of combustionfrom the upper drums to the lower one, and a discharge pipecommunicating with the rear central portion of the lower drum andleading to a point of discharge.

2. In a device of the class described, the combination of a combustionchamber, a furnace wall surrounding the combustion chamber and arrangedeccentrically relative thereto, the front of the furnace wall beingcloser to the combustion chamber than the other parts, two radiatingdrums at the upper portion of the space between the combustion chamberand the furnace wall, each of said upper radiating drums having its rearend spaced apart from a rear central line, and being extended to a pointspaced apart from the front central line, and also being tapered from amaximum width at its rear end to a minimum at its front end, means forproviding communication direct from the upper portion of the combustionchamber to the rear end of each radiating drum, a radiating drum belowthe upper drums extended from points spaced apart from a front centralline all around the space between the combustion chamber and the furnacewall, pipes communicating between the front ends of the upper drums andthe front ends of the lower drum to convey I the products of combustionfrom the upper drums to the lower one, and a discharge pipecommunicating with the rear central portion of the lower drum andleading to a point of discharge, said pipe being extended upwardlybetween the rear ends of the upper drums and then rearwardly through thefurnace wall.

3. In a device of the class described, the combination of a combustionchamber, a furnace wall surrounding the combustion chamher and arrangedeccentrically relative thereto, the front of the furnace wall beingcloser to the combustion chamber than the other parts, two radiatingdrums at the upper portion of the space between the combustion chamberand the furnace wall, each of said upper radiating drums having its rearend spaced apart from a rear central line, and being extended to a pointspaced apart from the front central line, and also being tapered from amaximum width at its rear end to a minimum at its front end, means forproviding communication direct from the upper portion of the combustionchamber to the rear end of each radiating drum, a radiating drum belowthe upper radiating drums, extending from points spaced apart from afront central line all around the space between the combustion chamberand the furnace wall, pipes communicating between the front ends of theupper drums and the front ends of the lower drum to convey the productsof combustion from the upper drums to the lower one, a discharge pipecommunicating with the rear central portion of the lower drum andleading to a point of discharge, said pipe being extended up 'ardlybetween the rear ends of the upper drums and then rearwardly through thefurnace wall, and an open-ended pipe in the center of said dischargepipe so arranged that the products of combustion passing through thedischarge pipe will surround the open-ended pipe and heat the airpassing upwardly through said open-ended pipe.

4. In a device of the class described, the combination of a combustionchamber, a furnace wall surrounding the combustion cham her and arrangedeccentrically relative thereto, the front of the furnace wall beingcloser to the combustion chamber than the other parts, two radiatingdrums at the upper portion of the space between the combustion chamberand the furnace wall, each of said upper radiating drums having its rearend spaced apart from a rear central line, and being extended to a pointspaced apart from the front central line, and also being tapered from amaximum width at its rear end to a minimum at its front end, means forproviding communication direct from the upper portion of the combustionchamber to the rear end of each radiating drum, a radiating drum belowthe upper radiating drums extended from points spaced apart from a frontcentral line all around the space between the combustion chamber and thefurnace wall, pipes communicating between the front ends of the upperdrums and the front ends of the lower drum to convey the products ofcombustion from the upper drums to the lower one, a discharge pipecommunicating with the rear central portion of the lower drum andleading to a point of discharge, said pipe being extended upwardlybetween the rear ends of the upper drums and then rearwardly through thefurnace wall, and an openended pipe in the center of said discharge pipeso arranged that the products of combustion passing through thedischarge pipe will surround the open-ended pipe and heat the airpassing upwardly through said openended pipe, all of said radiatingdrums being provided near their forward portions with clean-outopenings.

Des Moines, Iowa, July 17 1908.

CARLISLE ST. JOHN.

